THIS TRIPARTITE syndrome presents symptoms (1) confined to the distribution of the great occipital nerve, (2) shared by the trigeminus, or (3) shown by the trigeminus alone, as a nociceptor to passive stimulation by the vulnerable great occipital nerve.
In every case alcohol block (Fig. 1) relieved all symptoms. Pinprick verification of numbness was made in all cases; it presaged relief lasting 6 to 12 months, permanent relief being more frequent than recurrence.
At times the needle piercing the great occipital nerve produced pain radiating to the homolateral supraorbital notch (Fig. 1; Table 3).
Most of the items in Table 3, together with relief of all symptoms on block of the great occipital nerve, suggest a functioning contact between the great occipital nerve and the trigeminus. According to Ramón y Cajal,* only those fibers derived from the ophthalmic division of the trigeminus reach the lowest level (C 2) of the